Where is the Prepar3D.cfg file, and how do I reset it?

Prepar3D stores Prepar3D.cfg in %APPDATA%\Lockheed Martin\[version folder]\ for the signed-in Windows user. To reset it, close Prepar3D, enable file-name extensions, rename the file to Prepar3D.cfg.bak, then restart the simulator. Prepar3D creates a fresh configuration; the renamed original remains available if you need to restore it.

Where exactly is the Prepar3D.cfg file?

The default location is the simulator’s version-specific folder inside Windows Roaming AppData. Press Windows key + R, enter %APPDATA%\Lockheed Martin, and open the folder matching the Prepar3D version you run.

Where is Prepar3D.cfg in v5?

For Prepar3D v5, the exact path is %APPDATA%\Lockheed Martin\Prepar3D v5\Prepar3D.cfg. Each major Prepar3D version has its own folder, so changing the v4 file will not reset v5.

Do not look in the Prepar3D installation directory under Program Files. The working user configuration belongs in AppData. nein simply means “no” in German; it is not a Prepar3D version, filename or configuration folder.

AppData is hidden by default, but the %APPDATA% shortcut opens it directly. If File Explorer displays the file as Prepar3D, check its Type and enable file-name extensions before renaming it.

Prepar3D.cfg or scenery.cfg: which one did you mean?

Use Prepar3D.cfg for the simulator’s per-user display, graphics and general configuration values; scenery.cfg controls scenery-library layers and is stored separately. If Prepar3D.cfg is the one you meant, stay in the version folder under AppData.

Changing the wrong file is a common mistake. For missing scenery areas, layer-order problems or Scenery Library work, see our explanation of where Prepar3D scenery.cfg is stored and how it differs.

How do I reset Prepar3D.cfg safely?

The safest reset is to rename the existing configuration rather than delete it. This preserves an immediate backup and prevents a bad reset from becoming irreversible.

1. Close Prepar3D completely. Wait for the simulator process to finish; otherwise it may overwrite the file while shutting down or keep it locked.
2. Show file-name extensions. Turn on File name extensions in File Explorer so you can see the full .cfg suffix. This avoids accidentally creating a name such as Prepar3D.cfg.bak.cfg.
3. Open the correct version folder. Press Windows key + R, enter %APPDATA%\Lockheed Martin, then choose the folder for the major version you actually launch.
4. Make a separate backup. Copy Prepar3D.cfg to a safe location in case the in-folder backup is later overwritten or removed.
5. Rename the working file. Change Prepar3D.cfg to Prepar3D.cfg.bak. If that name already exists, use another unique backup name.
6. Start Prepar3D. With no file named Prepar3D.cfg present, the simulator generates a clean replacement using default and hardware-detected values.
7. Test the original symptom first. Use the same scenario that exposed the fault, preferably with a default aircraft and uncomplicated airport where add-ons are not required.
8. Reapply settings gradually. Change one group of options at a time. Do not immediately paste every old tweak into the clean file, as that can restore the original fault.

If only one known entry needs changing, a full reset is unnecessary. Follow our safe procedure for backing up and editing Prepar3D.cfg instead.

Should I reset the cfg, edit it, or leave it alone?

Reset the file when you need a clean diagnostic baseline; edit it when you know the specific setting involved.

A cfg reset does not rebuild every Prepar3D cache, repair damaged programme files or remove a faulty add-on. Its value is diagnostic: if the problem disappears with the clean file, something in the old configuration was responsible.

What does resetting Prepar3D.cfg change?

Resetting replaces only the preferences and generated values held inside Prepar3D.cfg. This includes display and graphics options, along with other simulator settings and any custom entries that an add-on or manual tweak placed in that file.

• Installed aircraft, scenery and texture files are not deleted.
• Prepar3D activation and licence information are not reset.
• Scenery-library layers stored in scenery.cfg are not rebuilt.
• Settings and add-on registrations stored in other files remain in place.
• An add-on that requires a custom cfg entry may need its configuration utility run again.

Do not copy an entire Prepar3D.cfg from one major version into another. Supported options and hardware-generated values can differ, so recreate the needed settings in the file generated by that version.

Can I restore my old Prepar3D configuration?

You can restore the old configuration by closing Prepar3D and putting the backed-up file back under its original name.

1. Close Prepar3D.
2. Rename the clean file to something such as Prepar3D.cfg.clean if you want to retain it.
3. Rename the backup from Prepar3D.cfg.bak to Prepar3D.cfg.
4. Restart and test. If the fault returns, the old configuration contains the cause.

When the clean file fixes the problem, we recommend keeping it and recreating only the settings you need. Restoring the whole backup is quicker, but it can also restore the damaged or incompatible entry.

What if nothing shows in the Prepar3D folder?

If nothing shows, the usual causes are a hidden extension, the wrong version folder, the wrong Windows account or a cfg that has not yet been generated.

• Use the Run shortcut: enter %APPDATA%\Lockheed Martin rather than trying to expose AppData manually.
• Check the major version: v5 uses Prepar3D v5, while v6 uses Prepar3D v6. Multiple installations do not share one cfg.
• Check the Windows account: AppData is per user. Prepar3D run under another account uses that account’s configuration folder.
• Launch and exit once: a version that has never completed an initial launch may not yet have written its cfg.
• Show extensions: the file may appear only as Prepar3D with a CFG file type.
• Verify the rename: make sure no file is still named Prepar3D.cfg and that the backup did not acquire an extra hidden extension.
• Check write access: if Prepar3D cannot create files in its AppData folder, correct the Windows account or folder-permission problem rather than placing the cfg in Program Files.

If a fresh cfg is created but the crash or loading failure remains, the configuration file is probably not the root cause. Continue with our step-by-step Prepar3D crash-isolation process to separate add-on, scenery, driver and installation faults.